Feature technology : an overview

The proper integration of the activities of computer-aided design (CAD) and computer-aided manufacture (CAM)is an objective that has become more urgent within the wider context of a total computer integrated manufacturing (CIM) environment. In seeking this integration it is recognized that the diversity of activities and consequent needs for data can best be served by a single representation for design, design analysis and manufacturing planning, and that a strong candidate for this descriptive role is a feature representation. This paper briefly overviews the primary methods of the use of features through feature recognition and design by features, particularly in the process planning application area

Feature technology - an overview

Manufacture is an objective that has become more urgent within the wider context of a total Computer Integrated Manufacturing environment. In seeking this integration it is recognised that the diversity of activities and consequent needs for data can best be served by a single representation for design, design analysis and manufacturing planning, and that a strong candidate for this descriptive role is a Feature Representation. This paper briefly overviews the primary methods of the use of features through Feature Recognition and Design by Features, particularly in the process planning application area

Process capability modelling: a review report of feature representation methodologies

Approximately 150 technical papers on the features methodology have been carefully studied and some selected papers have been commented upon. The abstracts of the comments are documented and attached to this report. The methodologies reviewed are mainly divided into two approaches, ie. feature recognition and design by features. Papers which deal with some specific topics such as feature taxonomies, dimensions and tolerances, feature concepts, etc. are also included in the document

Feature Extraction and Classification from Boundary Representation

In the paper, an algorithm for explicit feature extraction and classification from boundary representation is presented. It operates in two phases: the topological and the geometrical. While the topological part is just an adaptation of an already known algorithm, the geometrical part represents an original and new solution. In this part, the algorithm manipulates with features filled by material and the empty ones. The algorithm classifies extracted features into eight classes. It successfully and efficiently handles voids, nested features and many cases of mutual feature intersections. The time complexity depends on input data, and never exceeds O(n^2)

A knowledge-based approach for the extraction of machining features from solid models

Computer understanding of machining features such as holes and pockets is essential for bridging the communication gap between Computer Aided Design and Computer Aided Manufacture. This thesis describes a prototype machining feature extraction system that is implemented by integrating the VAX-OPS5 rule-based artificial intelligence environment with the PADL-2 solid modeller. Specification of original stock and finished part geometry within the solid modeller is followed by determination of the nominal surface boundary of the corresponding cavity volume model by means of Boolean subtraction and boundary evaluation. The boundary model of the cavity volume is managed by using winged-edge and frame-based data structures. Machining features are extracted using two methods : (1) automatic feature recognition, and (2) machine learning of features for subsequent recognition. [Continues.

Feature Recognition for Interactive Applications: Exploiting Distributed Resources

The availability of low-cost computational power is a driving force behind the growing sophistication of CAD software. Tools designed to reduce time-consuming build-test-redesign iterations are essential for increasing engineering quality and productivity. However, automation of the design process poses many difficult computational problems. As more downstream engineering activities are being considered during the design phase, guaranteeing reasonable response times within design systems becomes problematic. Design is an interactive process and speed is a critical factor in systems that enable designers to explore and experiment with alternative ideas during the design phase. Achieving interactivity requires an increasingly sophisticated allocation of computational resources in order to perform realistic design analyses and generate feedback in real time. This paper presents our initial efforts to develop techniques to apply distributed algorithms to the problem of recognizing machining features from solid models. Existing work on recognition of features has focused exclusively on serial computer architectures. Our objective is to show that distributed algorithms can be employed on realistic parts with large numbers of features and many geometric and topological entities to obtain significant improvements in computation time using existing hardware and software tools. Migrating solid modeling applications toward a distributed computing framework enables interconnection of many of the autonomous and geographically diverse software tools used in the modern manufacturing enterprise. (Also cross-referenced as UMIACS-TR-94-126.1

Intelligent techniques for automatic feature recognition in CAD models

The solutions suggested in this research are implemented in a prototype AFR system and its performance verified on commonly used benchmarking parts that are composed of machining features.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Intelligent techniques for automatic feature recognition in CAD models

The solutions suggested in this research are implemented in a prototype AFR system and its performance verified on commonly used benchmarking parts that are composed of machining feature

Using a design by features CAD system for process capability modelling

Process capability modelling offers a method of matching the shape, technological and cost capabilities of manufacturing equipment to the requirements of components, singly or as groups. This provides the basis of planning tools useful in the capital intensive business of the construction of new manufacturing facilities or the reconfiguration of existing ones. The success of this modelling approach is dependent upon having an appropriate representation of the design geometry. The representation must be such that all geometric inquiries raised by the process capability modelling are either explicitly held within some data representation or alternatively can be derived algorithmically by reference to a geometric model. The representation must also be capable of withstanding the rigours of use within the wider context of implementing an important part of the CAM interface within a CIM environment. This paper describes a feature-based representation based on a feature taxonomy which uses External Access Directions (EAD) as the characterizing aspect of geometry. These EADs become potential machining directions for a collection of features on a component, and are used as an essential link into generative process planning activities. The representation has been used in conjunction with process planning and process capability modelling applications. This paper concentrates on the latter, where the feature representation has been embedded within a proprietary geometric modeller which has been provided with a purpose-built user interface. A feature-based component model is created by the geometric modeller and accessed by functions which enable flexible component grouping and matching to process capability through the concept of a composite component. Subsequent process component grouping within the context of particular manufacturing systems strategies (cellular manufacture, flow-line, etc.) ultimately results in functional machine descriptions and variants